static const float4 palette[16] = {
    float4(0x00 * 255 / 63, 0x00 * 255 / 63, 0x00 * 255 / 63, 0xff) / 0xff,
    float4(0x00 * 255 / 63, 0x00 * 255 / 63, 0x3f * 255 / 63, 0xff) / 0xff,
    float4(0x00 * 255 / 63, 0x2a * 255 / 63, 0x00 * 255 / 63, 0xff) / 0xff,
    float4(0x00 * 255 / 63, 0x2a * 255 / 63, 0x2a * 255 / 63, 0xff) / 0xff,
    float4(0x33 * 255 / 63, 0x00 * 255 / 63, 0x00 * 255 / 63, 0xff) / 0xff,
    float4(0x2f * 255 / 63, 0x1c * 255 / 63, 0x37 * 255 / 63, 0xff) / 0xff,
    float4(0x23 * 255 / 63, 0x14 * 255 / 63, 0x00 * 255 / 63, 0xff) / 0xff,
    float4(0x2f * 255 / 63, 0x2f * 255 / 63, 0x2f * 255 / 63, 0xff) / 0xff,
    float4(0x15 * 255 / 63, 0x15 * 255 / 63, 0x15 * 255 / 63, 0xff) / 0xff,
    float4(0x00 * 255 / 63, 0x2f * 255 / 63, 0x3f * 255 / 63, 0xff) / 0xff,
    float4(0x00 * 255 / 63, 0x33 * 255 / 63, 0x15 * 255 / 63, 0xff) / 0xff,
    float4(0x15 * 255 / 63, 0x3f * 255 / 63, 0x3f * 255 / 63, 0xff) / 0xff,
    float4(0x3f * 255 / 63, 0x27 * 255 / 63, 0x23 * 255 / 63, 0xff) / 0xff,
    float4(0x3f * 255 / 63, 0x15 * 255 / 63, 0x3f * 255 / 63, 0xff) / 0xff,
    float4(0x3b * 255 / 63, 0x3b * 255 / 63, 0x00 * 255 / 63, 0xff) / 0xff,
    float4(0x3f * 255 / 63, 0x3f * 255 / 63, 0x3f * 255 / 63, 0xff) / 0xff,
};
